1256891244447 has 16 divisors (see below), whose sum is σ = 1686412645632. Its totient is φ = 832663562880.

The previous prime is 1256891244431. The next prime is 1256891244449. The reversal of 1256891244447 is 7444421986521.

It is a happy number.

It is not a de Polignac number, because 1256891244447 - 2⁴ = 1256891244431 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1256891244449) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1523643 + ... + 2198924.

It is an arithmetic number, because the mean of its divisors is an integer number (105400790352).

Almost surely, 2^{1256891244447} is an apocalyptic number.

1256891244447 is a deficient number, since it is larger than the sum of its proper divisors (429521401185).

1256891244447 is a wasteful number, since it uses less digits than its factorization.

1256891244447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3723278.

The product of its digits is 15482880, while the sum is 57.

The spelling of 1256891244447 in words is "one trillion, two hundred fifty-six billion, eight hundred ninety-one million, two hundred forty-four thousand, four hundred forty-seven".